Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 9, pp. 1404−1409.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © N.V. Baranova, L.A. Pashina, S.A. Bogdanova, A.V. Kostochko, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 9,
AND POLYMERIC MATERIALS
Energy and Acid–Base Characteristics
of the Surfaces of Polymeric Modiﬁ ers
for Filled Cellulose Nitrate Composites
N. V. Baranova, L. A. Pashina, S. A. Bogdanova, and A. V. Kostochko
Kazan National Research University of Technology, Kazan, Tatarstan, Russia
Received June 7, 2013
Abstract—The energy and acid–base characteristics of the surface of butadiene–nitrile (SKN-18, SKN-26,
SKN-40) and urethane (SKU-8А, SKU-8TB) rubbers, and also of polyvinyl nitrate and polyvinyl butyral were
determined. Butadiene–nitrile rubbers are characterized by the highest, and vinyl polymers, by the lowest free
surface energy. The free surface energy of urethane rubbers has intermediate values. The results obtained show
that the surface energy of the polymers is determined both by the chemical nature of functional groups located
directly in the surface layer and by the macromolecular packing density. The surface acidity increases in the order
polyvinyl butyral < polyvinyl nitrate < SKU < SKN. The nature of the surface of the polymers under consideration
is determined by prevalence of certain acid–base sites of adhesion interaction as a result of conformational turns
of macromolecular chain segments.
One of the most efﬁ cient ways to control the perfor-
mance of heterogeneous polymer systems is enhancement
of the adhesion interaction at the phase boundary by
modifying the crystalline ﬁ ller surface with macromo-
Comparison of the previously determined energy and
acid–base characteristics of cellulose nitrates and nitra-
mine ﬁ llers [1, 2] shows that the adhesion interaction in
cellulose nitrate composites is weak. Therefore, the goal
of this study is search, based on thermodynamic aspects
of the adhesion theory, for polymers that would improve
the physicomechanical properties of ﬁ lled systems when
used for modifying the crystalline ﬁ ller surface.
The applications of cellulose nitrate compounds are
very speciﬁ c and are largely determined by the relation-
ships of combustion. Therefore, the modifying polymer
should not appreciably increase the molecular weight of
combustion products and contain heavy elements (sulfur,
halogens, silicon). It is also necessary to take into account
such factors as compatibility of the modifying polymer
with cellulose nitrate and its availability.
Therefore, we chose in this study butadiene–nitrile
and urethane rubbers and vinyl polymers. To evaluate
the possibility of enhancing the interfacial interactions in
cellulose nitrate composites ﬁ lled with nitramine ﬁ llers by
modifying the ﬁ ller surface, we estimated the energy and
acid–base characteristics of surfaces of these polymers.
Experiments were performed with the following
macromolecular compounds: butadiene–nitrile rubbers
with different content of nitrile groups [SKN-18, SKN-
26, SKN-40, TU (Technical Speciﬁ cation 38-30301-
41–92)], polyurethane millable rubbers [SKU-8А (TU
38.103209–77) and SKU-8TB (TU 38.103468–80)],
and vinyl polymers: polyvinyl nitrate (PVN) (ММ
550 000–607 000) and polyvinyl butyral [PVB, GOST
(State Standard) 9439–85].
The structural formulas of the elementary units of the
polymers are given in Table 1.
The energy and acid–base characteristics were de-